A Rapid Technique for Preparing Microorganisms for Transmission Electron Microscopy

Publisher Website
Google Scholar
Abstract
A rapid and efficient method of preparing microorganisms for transmission electron microscopy is reported. In developing the method, Salmonella heidelberg, Streptococcus pyogenes and ciliated protozoal specimens were fixed with glutaraldehyde. After fixation cells are collected on a membrane filter, washed with buffer, postfixed with OSO4, then washed with distilled water and stained en bloc with uranyl acetate. Specimens were dehydrated using a graded series of acetone and then infiltrated with graded mixtures of acetone and Spurr embedding medium. The membrane filter finally is cut into small pieces and embedded in fresh embedding medium polymerized in polyethylene capsules. By collecting and processing the specimens on membrane filters, numerous centrifugations are eliminated from standard procedures. The use of a low viscosity embedding medium allows for rapid infiltration and embedding of the specimen. Using this technique, microbial specimens can be sectioned after < 4 h preparation.